This invention relates to an elongate body side moulding suitable for attachment to the side of a vehicle body and to a vehicle with such a moulding attached.
In the automotive industry, it is relatively common to fit elongate mouldings of elastomeric material to the side body panels of a vehicle. Such mouldings are decorative and afford a degree of protection to the vehicle body upon side impact. The mouldings form a physical barrier to objects in a side-on collision and have a degree of deformability which will absorb a low-impact blow. The mouldings therefore protect the vehicle to an small extent from damage such as denting the body panels or scratching the paintwork.
Such mouldings may also comprise one or more metal strip(s) or a metal core, which is included to prevent the moulding from shrinking to a significant extent at low temperatures, in other words the metal strip gives the moulding temperature length stability. The metal strip also gives the moulding a degree of lateral stiffness.
One problem associated with body side mouldings which comprise metal strip(s) is that, at low temperatures, they have a tendency to become detached from the side of the vehicle body. As the elastomeric material has a higher coefficient of thermal expansion than the metal, the moulding is caused to bend at low temperatures, so that the ends of the moulding lift off from the side of the vehicle (as shown in FIG. 2).
This effect is reduced to a certain extent in body side moulding designs in which the metal strip is located within the elastomeric material (as shown in FIG. 3). However, the propensity for such mouldings to become detached from the vehicle at low temperatures is dependent on the location of the metal strip within the moulding.
According to a first aspect of the present invention there is provided an elongate body side moulding suitable for attachment to the side of a vehicle body, which moulding comprises:
i) one or more stabilising strip(s);
ii) one or more layer(s) of a polymeric material with a relatively high coefficient of thermal expansion; and
iii) one or more layer(s) of a polymeric material with a relatively low coefficient of thermal expansion;
the layers of polymeric material with high and low coefficients of thermal expansion being so arranged that, even at relatively low temperatures, the overall shape of the body side moulding is substantially maintained.
In particular, the layers of polymeric material with high and low coefficients of thermal expansion are so arranged that, even at relatively low temperatures, the body side moulding does not curve significantly about an axis parallel to the general plane of the strip(s) and perpendicular to the length of the strip(s).
According to a second aspect of the present invention there is provided an elongate body side moulding suitable for attachment to the side of a vehicle body, which moulding comprises:
i) one or more stabilising strip(s);
ii) one or more layer(s) of a polymeric material with a relatively high coefficient of thermal expansion; and
iii) one or more layer(s) of a polymeric material with a relatively low coefficient of thermal expansion;
wherein the layers of polymeric material with high and low coefficients of thermal expansion are so arranged that, when the moulding is attached to the side of a vehicle body, and subjected to relatively low temperature, the moulding tends to curve, about a axis parallel to the general plane of the strip(s) and perpendicular to the length of the strip(s), such that the two ends of the moulding are urged towards the side of the vehicle body.
Preferably the moulding comprises a first layer and a second layer wherein:
i) the first layer is made from the polymeric material with the relatively low coefficient of expansion and, when the moulding is fitted to the side of a vehicle body, is relatively far from the vehicle body;
ii) the second layer is made from the polymeric material with the relatively high coefficient of expansion and, when the moulding is fitted to the side of a vehicle body, is relatively close to the vehicle body; and
iii) the stabilising strip is positioned between the first and second layers.
According to a third aspect of the present invention there is provided a vehicle which has fitted to it a moulding according to the first or second aspect of the present invention.
By using two kinds of elastomeric materials (with different coefficients of thermal expansion) the present inventors have shown that it is possible to reduce the extent to which metal-containing body-side mouldings curve such that they become detached from the vehicle body. It is also possible to control the curvature, so that at low temperatures, the moulding tends to curve in such a way that the ends are pushed on to the vehicle body side. A further advantage of the body side moulding in accordance with the present invention is that their propensity for curvature at low temperatures is less sensitive to the location of the stabilising strip on or in the moulding.